SPARTA, Ky. - A day after Danica Patrick was referred to as a "marketing machine" and "not a race car driver" by a TV analyst and former driver, current drivers defended the rookie Sprint Cup Series driver.

Kyle Petty said on SPEED's RaceHub program Thursday that Patrick "can go fast, but she can't race."

"I think she's come a long way, but she's still not a race car driver," he said. "And I don't think she's ever going to be a race car driver."

That doesn't mean Petty's opinion is shared by others.

"I have to disagree with Kyle," Dale Earnhardt Jr. said Friday at Kentucky Speedway. "I think she's a tough competitor. She works really hard at what she does and she has run some really good races. On every occasion, she's outrunning several guys on the circuit.

"If she was not able to compete or not able to run minimum speed or finishing in last place every week, I think you might be able to say Kyle has an argument. But she's out there running competitively and running strong on several accounts."

Patrick has finished in the top 15 only three times in 16 races this year. She has not led any laps or had a top-10 finish since her eighth-place result in the Daytona 500 to open the season.

But Earnhardt, Patrick's former boss when she drove in the Nationwide Series for JR Motorsports, noted she's been running well enough that she "might surprise even Kyle Petty" at some point.

Kevin Harvick said Petty's comments were "a loaded gun" and said there was no real training ground for the amount of horsepower drivers experienced in the Sprint Cup Series. He said it was "really hard to understand what you need to drive these cars."

"To drive them fast is something that is just not going to happen overnight," Harvick said. "I don't know that I would go as far as calling her not a racer because she's raced her whole life and I think on a continuous learning curve. She's obviously dedicated at what she does to try to get better and knows she has a lot of hurdles to overcome in a short amount of time."

Harvick, her future teammate at Stewart-Haas Racing (he joins the team next year), said Patrick was lucky to have sponsor Go Daddy in her corner, because it gave her an opportunity to learn, even if she was struggling.

And the criticism, he said, was something all drivers experience.

"Being around her the little bit I have, she seems to have become immune to it and understands the goal," he said. "I think she's realistic with her goals and understands she has a lot to learn and tries to take everything in. It's easier to turn it all off - not read it, not listen to it. ... It's easier just to not pay attention to it. If you can make yourself do that, life is a lot better."

Jimmie Johnson wasn't asked about Petty's comments specifically, but said Patrick's learning curve was similar to other open-wheel drivers he's seen, such as Dario Franchitti and Sam Hornish Jr.

Johnson said he's told friends from other series to have a "five-year plan" if they want to be successful in stock cars, because the adjustment is difficult.

"IndyCar guys and girls don't have a lot of side-by-side racing," he said. "... It takes awhile to figure it out. They're different cars and the racing that takes place on the track - the door-to-door racing... that's just something that takes laps."

Patrick is expected to address the media as part of her weekly interview session at 3:30 p.m. Eastern.